Read Horizon producer/director Charles Colville's article about comet ISON at BBC News.
- Comet ISON approaches the Sun Duration: 01:57 2013-2014, Comet of the Century: A Horizon Special
- Origins of the Solar System Duration: 04:06 2013-2014, Comet of the Century: A Horizon Special
- ISON - the comet of the century? Duration: 00:57 2013-2014, Comet of the Century: A Horizon Special
- Dr Mary Schweitzer's quest to find ancient biological material Duration: 02:18 2013-2014, Dinosaurs: The Hunt for Life
- Finding smuggled bones in Mongolia Duration: 01:23 2013-2014, Dinosaurs: The Hunt for Life
- Mary's first discovery. What looked like the blood cells of a 66 million year old T-rex Duration: 03:11 2013-2014, Dinosaurs: The Hunt for Life
More about comets
Watch and listen to clips from past BBC programmes about these icy visitors from the outer reaches of the Solar System.
The secret life of the cat
Watch over 200 Horizon clips
Horizon has covered some of the most important scientific issues of recent decades, and this extensive back catalogue has over 200 short clips from as far back as the late Sixties.
Video quiz: Is seeing believing?
See if your senses are fooled by some of the cleverest optical illusions ever created, and find out how they work. As well as being fun, they’re also helping scientists learn more about how we interpret the world around us.